Re: Microwave Oven Transformers (MOTs)

Hi all!
    I can now agree with you on that.  I realized a few things
about my setup that contributed to the results I found..
1.  My MOT is older than dirt, and expired recently.
2.  Big Duh...my power board was running a single 12amp breaker...I
frequently switch between inside and out, and it's easier for me
just to use a line filter box /w it's 12A breaker than to keep
changing my breaker in the box.  I have 2 of these filters in
parallel, (24A), but rarely use that setup.. they weigh a ton.
My MOT is undergoing an autopsy this weekend (if I got time!)...
    So I stand corrected myself, and I intend to get a coupla' more
MOTS to check out...definately interesting little beasties, and
hopefully these will last a bit longer.


-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Thursday, May 04, 2000 2:19 AM
Subject: Re: Microwave Oven Transformers (MOTs)

>Original Poster: "Gregory R. Hunter" <ghunter-at-accucomm-dot-net>
>At 07:27 AM 05/02/2000 -0600, you wrote:
>>Original Poster: "sundog" <sundog-at-timeship-dot-net>
>>Hi!  MOTs must be ballasted, because unlike NST's or OBIT's, they
>>don't have current-limiting shunts that keep the core from
>>saturating and dumping as much current as it can till either the
>>wires burn up, the breaker/fuse goes, or someting else blows up
>>(read "Your Cap!")
>Hi Sundog, all
>This conflicts with my own experience.  My twin MOT supply with
>doublers is running unballasted on a 220V/20 Amp circuit, and it
has never
>tripped the breaker.  Likewise, I have tried the same power supply
with no
>voltage doublers and no ballast, and it still didn't trip the
>Also, I have tested a few 115V MOTs that did not trip a 20A/115V
>with the HV lead shorted to the core and the primary plugged into
a regular
>wall outlet.  The MOTs I tested in this way got hot, but did not
burn up or
>damage anything.  I agree that they are not designed to run in a
>short-circuit condition, but some MOTs regulate themselves better
>others.  Even so, if you wish to run more than one MOT on a single
>circuit, then ballasting is required.
>My $.02 worth,
>>-----Original Message-----
>>From: Tesla List <tesla-at-pupman-dot-com>
>>To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
>>Date: Monday, May 01, 2000 10:13 PM
>>Subject: Re: Microwave Oven Transformers (MOTs)
>>>Original Poster: Fucian-at-aol-dot-com
>>>Then why must they (MOTs) be ballasted?